An atom of oxygen has six electrons in its outermost ring and requires two more to become stable. What is the valence number of oxygen? Question 5 options: +6 +2 –2 –6 +6

+2

–2

–6

-2

EXPLANATION

Valence refers to the number of electrons that an atom must borrow or lend to complete its outermost shell. An atom of oxygen wants to add two more electrons to complete its outer shell of eight electrons. Since doing so would result in the oxygen atom becoming negatively charged by accepting two more electrons, oxygen is said to have a valence -2  

indium, and thallium have three electrons i think